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Modification To Thermistor based component.

Posted: Thu May 10, 2018 4:38 pm
by medelec35
Would it possible to choose whether the thermistor is connected to VSS or VDD?
My circuit has a pull-down resistor, so would be handy if can select either. :)

Martin

Re: Modification To Thermistor based component.

Posted: Fri May 11, 2018 11:46 am
by Benj
Hi Martin,

Yes that's a good idea. I'll have a play and see how easy it would be.

Re: Modification To Thermistor based component.

Posted: Fri May 11, 2018 4:33 pm
by Benj
Right here we go, I've added the change to the base component and exposed that on the next level up,
Thermistor_base.fcpx
(3.94 KiB) Downloaded 237 times
EBM003_Thermistor.fcpx
(83.96 KiB) Downloaded 244 times
Have a play and let me know how you get on.

Re: Modification To Thermistor based component.

Posted: Fri May 11, 2018 4:39 pm
by medelec35
Thanks Ben,
Will try it out both ways and will let you know how I got on.
Thinking ahead will it work in V8 when released as well?

Re: Modification To Thermistor based component.

Posted: Fri May 11, 2018 4:52 pm
by Benj
Yes I've already applied the mod to the v8 components so fingers crossed this will work well :D

I've done a lot of recent v7 mods (all of which have been propagated to v8) and so if this works ok then I'll try and do another zip file update so that all the recent v7 bug fixes and additions can be found in a single place.

Re: Modification To Thermistor based component.

Posted: Mon May 14, 2018 10:00 am
by medelec35
Hi Ben,
Mods appear to be working a treat!

Testing on hardware comparing with thermometer and K type thermocouple.

The only minor thing is I entered Min Temp as 0 and Max Temp of 100 as that's the limits cover by the data sheet.
however component still requires -25 and +125 which had to be based on a generic calculation using beta so may affect accuracy?

Martin

Re: Modification To Thermistor based component.

Posted: Mon May 14, 2018 10:26 am
by LeighM
Hi Martin,
That's OK, it will not affect accuracy between 0 and 100
Leigh

Re: Modification To Thermistor based component.

Posted: Mon May 14, 2018 10:32 am
by medelec35
Hi Leigh,
Thank you.
So values outside limits can be left at 0?
Reason for asking is people may not have even rough values to hand.
If OK to put 0, then could that information go in the Wiki help please?

Re: Modification To Thermistor based component.

Posted: Mon May 14, 2018 11:10 am
by LeighM
Hi Martin,
Ah, good point, no, 0 will not work, they would have to be "sensible" values,
i.e. if 0 deg C has the highest (resistance) value then -25 will need to be higher than that.
But the actual value will not matter, unless the temperature moves into that zone.
The component uses linear approximation between the sample points.